Research Shows Nutritional Benefits of Pasture-Raised Products

Health-conscious consumers interested in increasing their intake of certain fatty acids in meat and dairy are driving the growth of pasture-raised livestock systems. To meet that demand, farmers in Iowa and Wisconsin asked their local Resource Conservation and Development Council to help measure the presence of those fats—conjugated linoleic (CLA) and omega-3—in their beef and milk.

Sixteen farmers wanted to maximize the CLA and omega-3 acid content of their beef and milk and take proof to their customers. “Producers had heard about CLA and wanted to find out what you do to raise an animal that has higher CLA in the food product,” said Lora Friest, NRCS coordinator of the Northeast Iowa RC&D, which paired with Iowa State University (ISU) researchers on a SARE-funded project assessing CLA concentrations.

One of the omega-3 fatty acids, linolenic acid has an anti-inflammatory effect in the body, which may lessen heart disease, said Don Beitz, an ISU professor of animal science and bio-chemistry. In lab tests on animals, CLA helped prevent cancer and heart disease.

Project partners split groups of animals on participating farms to compare CLA content of milk and beef raised on pasture versus hay, silage, and corn. Their results confirmed that beef and dairy products from grazing animals contain higher CLA content than food from non-grazing animals: 3- to 4-fold greater in milk and 1½ to 2 times greater for beef.

Dan Specht, a beef and pork producer in McGregor, IA, saw a difference in CLA content in beef from steers raised 100 percent on pasture. While he used to sell his beef to a cooperative, he has eliminated grain from the steers' diets and now sells his product with a “grass-fed” label at various markets for a premium price. “I'm sensitive to my bottom line and what I can make money on,” Specht said, “and the greatest demand out there is for grass-fed organic beef.”

The evidence for the health benefits of omega-3s and CLA is mixed, with data stronger for some fatty acids than for others, according to Kate Clancy, author of the 2006 study, Greener Pastures: How Grass-Fed Beef and Milk Contribute to Healthy Eating .

“The amounts of the fatty acids in grass-fed foods are relatively small on a per-serving basis,” Clancy said. “We need more research on what levels are needed in the diet to produce a health benefit. And we don't want to forget that there are many environmental and animal health benefits from grazing.”